<!-- 地区销售排行 -->
<template>
  <div class="com-container">
    <div class="com-chart" ref="rank_ref"></div>
  </div>
</template>

<script>
import { mapState } from 'vuex';
export default {
  data() {
    return {
      chartInstance: null,
      allData: null,
      startValue: 0, // 区域缩放的起点值
      endValue: 9, // 区域缩放的终点值
      timerId: null, // 定时器的标识
    };
  },
  mounted() {
    this.initChart();
    this.getData();
    window.addEventListener("resize", this.screenAdapter);
    this.screenAdapter();
  },
  destroyed() {
    window.removeEventListener("resize", this.screenAdapter);
    clearInterval(this.timerId);
  },
  computed:{
    ...mapState(['theme'])
  },
  watch:{
    theme(){
      console.log("主题切换了");
      this.chartInstance.dispose(); // 销毁当前的图表
      this.initChart(); // 以新主题切换图表对象
      this.screenAdapter(); // 完成屏幕适配
      this.updateChart(); // 更新图表展示
    }
  },
  methods: {
    initChart() {
      this.chartInstance = this.$echarts.init(this.$refs.rank_ref, this.theme);
      const initOption = {
        title: {
          text: "| 地区销售排行",
          left: 20,
          top: 20,
        },
        grid: {
          // 坐标轴配置
          top: "40%",
          left: "5%",
          right: "5%",
          bottom: "5%",
          containLabel: true,
        },
        tooltip: {
          // 鼠标移动上提示
          show: true,
        },
        xAxis: {
          type: "category",
        },
        yAxis: {
          type: "value",
        },
        series: [
          {
            type: "bar",
          },
        ],
      };
      this.chartInstance.setOption(initOption);

      this.chartInstance.on("mouseover", () => {
        clearInterval(this.timerId);
      })

      this.chartInstance.on("mouseout", () => {
        this.startInterval();
      })
    },
    async getData() {
      // 获取服务器数据
      const { data: ret } = await this.$http.get("rank");
      this.allData = ret;
      console.log(this.allData);
      this.allData.sort((a, b) => {
        return a.value - b.value;
      });

      this.updateChart();
      this.startInterval();
    },
    updateChart() {
      const colorArr = [
        ["#0BA82C", "#4FF778"],
        ["#2E72BF", "#23E5E5"],
        ["#5052EE", "#AB6EE5"],
      ];

      // 处理图表需要的数据
      // 所有省份所形成的数组
      const provinceArr = this.allData.map((item) => {
        return item.name;
      });

      // 所有省份对应的销售金额
      const valueArr = this.allData.map((item) => {
        return item.value;
      });

      const dataOption = {
        xAxis: {
          data: provinceArr,
        },
        dataZoom: { // 横向缩放数据
          show: false, // 底下滑动不显示
          startValue: this.startValue,
          endValue: this.endValue
        },
        series: [
          {
            data: valueArr,
            itemStyle: { // 每个柱的样式
              color: (arg) => { // 颜色
                let targetColorArr = null;

                if (arg.value > 200) {
                  targetColorArr = colorArr[0];
                } else if (arg.value > 100) {
                  targetColorArr = colorArr[1];
                } else {
                  targetColorArr = colorArr[2];
                }
                return new this.$echarts.graphic.LinearGradient(0, 0, 0, 1, [
                  {
                    offset: 0,
                    color: targetColorArr[0],
                  },
                  {
                    offset: 1,
                    color: targetColorArr[1],
                  },
                ]);
              },
            },
          },
        ],
      };
      this.chartInstance.setOption(dataOption);
    },
    screenAdapter() {
      const titleFontSize = this.$refs.rank_ref.offsetWidth / 100 * 3.6;
      const adapterOption = {
        title: {
          textStyle: {
            fontSize: titleFontSize
          }
        },
        series:[
          {
            barWidth:titleFontSize, // 柱的宽度
            itemStyle:{
              barBorderRadius: [titleFontSize / 2, titleFontSize / 2, 0, 0], // 柱的圆角
            }
          }
        ]
      };
      this.chartInstance.setOption(adapterOption);
      this.chartInstance.resize();
    },
    startInterval(){
      if(this.timerId){
        clearInterval(this.timerId);
      }
      this.timerId = setInterval(()=>{
        this.startValue++;
        this.endValue++;

        if(this.endValue > this.allData.length - 1){
          this.startValue = 0;
          this.endValue = 9;
        }

        this.updateChart();
      },2000);
    }
  },
};
</script>

<style lang='less' scoped>
</style>
